1. Field of the Invention
The present invention relates to an apparatus for detecting magnetic and electromagnetic waves or fields through use of non-superconducting materials. The present invention relates to apparatus which are used to measure such fields in order to predict earthquakes, volcanic eruptions and other violent earth movements which generate substantial abberations in magnetic and electromagnetic fields. The present invention can be used to detect any fluctuating magnetic or electromagnetic fields regardless of their origin. The present invention incorporates the use of antennae for the electromagnetic components and coils to detect magnetic fields, in conjunction with electronic elements involving amplification, smoothing elements, frequency response networks, networks to make frequency response uniform within the band and notch filters where necessary. The invention can be used to detect field emissions of electromagnetic and magnetic waves within the range of approximately 0.1 to 50,000 Hertz for magnetic field detection and approximately 1 kilohertz to 1 megahertz using a calibrated loop or other antennas for electromagnetic detection. Other applications involve the detection, measurement and characterization of magnetic and electromagnetic fields from other geophysical sources, storm fronts, upper atmospheric/ionospheric disturbances from solar wind activation effects, etc. The invention can be used to measure emissions from Video display terminals or other equipment emitting magnetic or electromagnetic fields within the bandwidth of the invention. Determination can be made of ELF/VLF emissions of possible biological significance to those exposed to or who operate VDTs, or who live or work near areas emitting low level fields of natural or artificial origin.
2. Description of the Prior Art
Relevant prior art extends back to 1876 with the invention of the telephone by Alexander Graham Bell. Improvements in the form of combination of a coil, diaphram and magnet in the telephone receiver were made which were used to detect magnetic field changes created by acoustic activation. Electric impulses were generated which varied directly with the acoustic waves transmitted by the telephone transmitter and sent these electric impulses over wires to the coil-diaphragm-magnetic core. These fundamental discoveries have led over the years to magnetic field coil detection apparatus of more sophistication and sensitivity in uses varying from oil location to detection of magnetic changes in the human heart and brain.
In prior art applications of magnetic detection apparatus, the core of the coil was usually made of soft iron or high permeability ferromagnetic material. These systems have suffered from limited bandwidths, poor frequency response and signal to noise ratios. Improvements in the core material have been made, but improvements have only led to field detection with inadequate sensitivity and poor resolution. Earthquake, weather, lightning and Geologic frequencies are in the approximate range of 0.1 Hertz to 30 KiloHertz and vary in magnetic amplitude from about 0.001 microgauss to a few milligauss, depending upon detection distance from the source. Therefore, significant frequencies are not detected with prior art detection apparatus using previously known coils, including improved coils with cores of mumetal.
Another problem with prior art magnetic or electromagnetic apparatus is that the apparatus can only detect certain catastrophic events such as an earthquake or volcanic eruption either during or after the event but not sufficiently in advance of the event to allow for a prediction of the exact time or location of the occurrence and to allow for preventive measures. The usual geologic activity detection devices such as seismographs are primarily mechanical in nature and only respond to mechanical earth movements. The inventors have experimentally determined that catastrophic events such as an earthquake or volcanic eruption is preceeded by certain subtle electromagnetic and magnetic impulse and sine waves of characteristic shapes and specific frequencies which are caused by movements below the mantle of the earth which extends downward to beyond ten miles from the earth's surface. Such deep magmatic or physical movements within the earth generate fields of magnetic flux which move and interact with the steady state magnetic fields of the earth. Since the earth is constantly rotating, such generated magnetic fields create subtle "wiggles" in the earth's steady state magnetic field between the earth's core and the ionosphere. Such changes within the ionosphere can also be due to heavy particle interactions from solar flare and other activity. Such very fine fluctuations can be precursers to a catastrophic event such as an earthquake. However when they are generated as just described, they are not capable of being detected by presently known apparatus. With presently known apparatus, the time constant is too long to measure those frequencies which allow for prediction of the earthquake. These prior art apparatus are unable to detect electromagnetic pulsations or magnetic pulsations which occur well in advance of (such as 72 hours before) the occurrence of the actual event. Present day researchers are primarily focused on mechanical predictions through use of apparatus such as a seismograph or lasers, and have not appreciated the importance of measuring the subtle and low intensity electromagnetic or magnetic characteristics which can be used to predict the event.
A device which can be used in conjunction with a seismograph is a superconducting quantum interference detector, commercially known as a Squid. This is a very bulky piece of apparatus which incorporates the use of periodic charging with liquid nitrogen and liquid helium which therefore makes such apparatus expensive and dangerous. These devices are flown over the earth's surface in large planes such as the Boeing 747 and are used to map the earth's magnetic field intensity changes. Over a period of several years, daily chartings produce a history of changes which can be charted. However, reading such magnetic field changes does not enable one skilled in the art to predict a catastrophic event such as a volcanic eruption or earthquake because the device does not respond to field fluctuations of much over 2 Hertz. Therefore, although such a device is sensitive to magnetic flux, it does not measure the necessary frequency range to determine the precurser characteristic of seismic activity. The reason for the Squid's failure is that at frequencies much above 0 Hertz, a large impulse field will create a continuous current loop in the Josephson junction of the Squid, which deactivates the entire device. Therefore the Squid is only useful for measuring static magnetic fields above the earth's surface and cannot be used to detect the types of electromagnetic and magnetic fields which can be detected through the present invention.
Squids can also be used to detect the magnetic component of brain waves and heart waves, but in such an application the Squid must be shielded from other extraneous signals. Such shielding requires the use of very heavy and expensive mumetal or other equivalent shielding. While such shielding enables the Squid to detect the waves in the human brain or heart, the necessary shielding to enable it to perform this function shields out the magnetic field of the earth thereby rendering the device useless for detecting magnetic flucations of the earth which can be used to predict geologic activity.